1. Technical Field of the Invention
The present invention relates to borehole analysis, and more particularly, to a system and method for generating a 3D graphical representation of information pertaining to a borehole for failure analysis purposes.
2. Description of Related Art
During the drilling of boreholes, problems will many times develop involving breakouts or collapses within the borehole. Breakouts occur when one side of a borehole breaks down or collapses. A collapse involves a complete loss of integrity of the borehole side walls. Breakouts and collapses cause downtime for the rig drilling the borehole and are highly undesirable due to the costs involved with downtime problems. In order to overcome the problems caused by breakouts and collapses, correct and fast diagnosis of the causes of the borehole failure are necessary in order to reduce the rig downtime and prevent future problems.
Current diagnosis of borehole failures is done by interpreting two dimensional log curve data. The use of two dimensional log curves can disburse various diagnostic features from the data over several curves making the data difficult to interpret. Wellbore failure analysis using caliper data is difficult because the interpreter must create a mental picture of the wellbore by integration information from six logs, namely the gamma ray log (lithology); caliper arms 1/3, and 2/4 to determine the cross-sectional shape of the borehole and which diameter is a long axis; the orientation of the caliper 1 and 3 arm to determine the orientation of a long axis and to check if the tool rotation has stopped in the elongated section; the deviation angle of the borehole to determine if the wellbore section is vertical or inclined; and the deviation azmuith to determine if the elongation direction is correlated with the highside of the wellbore and therefore may not be a stress induced elongation and so remedial action may be very different. This process must be completed for every depth sample along the borehole, typically six inches. In practice, this interpretation process must be done whenever the borehole geometry changes.
It should be appreciated by those skilled in the art, that this is a tedious process that is not rigorously applied. This makes determinations of the reasons for a borehole failure much more difficult. Thus, some method of producing a three-dimensional model that allows one to visually correlate all of these variables would be greatly appreciated. Existing 3D visualizations and borehole renderings utilize UBI (ultrasonic borehole imager tool) data to generate the 3D images. However, none of these existing 3D techniques have provided the type of data necessary to support a rigorous borehole failure mode analysis. Thus, a technique for generating a 3D representation of a borehole that supports borehole failure mode analysis is greatly desired.